1. Field of the Invention
The present invention relates to a mold ejection mechanism of an injection molding machine. More particularly, the present invention relates to an ejection mechanism for ejecting out a mold from the injection molding machine through a lever manner.
2. Description of the Related Art
After a product is injection molded by using an ejection molding machine, a mold of the ejection molding machine has to be ejected out by a mold ejection mechanism thereof, so as to take out the product ejection molded.
FIG. 1 illustrates a side view showing a conventional mold ejection mechanism and the structure of the mold ejection mechanism and an injection molding machine 200. As illustrated in FIG. 1, a conventional mold ejection mechanism is simply an actuating cylinder 300 arranged on a platen 220 of a mold 210 of the injection molding machine 200, and an actuating ejector rod 310 of the actuating cylinder 300 contacts directly with the mold 210, so as to eject out the mold 210 through a straight pushing motion of the actuating ejector rod 310 of the actuating cylinder 300.
The actuating cylinder 300 generally includes a pneumatic cylinder and a hydraulic cylinder. The pneumatic cylinder uses air as a medium for a pushing motion of the actuating ejector rod, and although a gas leakage problem may appear after a period of operation time, yet the leaked gas does not pollute neighboring machine parts and environment. However, a pushing force of the pneumatic cylinder is apparently smaller than that of the oil hydraulic cylinder. Although the hydraulic cylinder may provide a greater pushing force, it uses oil as a medium for the pushing motion of the actuating ejector rod, and, when an oil leakage problem appears after a period of operation time due to gradually decreasing performance of an oil seal, the leaked oil will pollute neighboring machine parts and environment.
The aforementioned conventional straightforward mold ejection mechanism cannot overcome respective disadvantages of using the pneumatic or hydraulic cylinder. That is, the conventional mold ejection mechanism directly applies the actuating ejector rod 310 of the actuating cylinder 300 to the mold 210 straightforward. By this straightforward forcing, a force exerted by the actuating cylinder 300 is the same as that applied to the mold 210. At this time, if a pneumatic cylinder is used as a power source of the actuating cylinder 300, the mold 210 may not be pushed since the pneumatic cylinder cannot provide enough pushing force. Therefore, the actuating cylinder 300 currently used by a mold ejection mechanism of the injection molding machine is typically a hydraulic cylinder so as to provide the mold 210 with enough pushing force. However, as described above, the hydraulic cylinder has the disadvantage of oil leakage which will pollute neighboring machine parts and environment. Particularly, an actuating ejector rod 310 of the hydraulic cylinder directly contacts the mold 210, and may directly pollute the mold, thus causing inconvenience and troubles in cleaning and maintenance of the polluted machine parts.
The applicability of the conventional straightforward mold ejection mechanism is poor due to the foregoing reasons.